The invention relates to a head-mounted display comprising an image display system which is common for two separate light channels, and an optical system for projecting an image formed in the image display system in a right and a left exit pupil of the head-mounted display, the optical system comprising a hollow mirror, a beam splitter arranged between the hollow mirror and the image display system, and a first and a second light channel each comprising a folding mirror and an eyepiece having at least one lens element.
A head-mounted display of the type described in the opening paragraph is known from international patent application WO 96/05532. In the head-mounted display described in this application, a liquid crystalline image display panel is imaged on a left and a right exit pupil of the head-mounted display by means of a field lens, a hollow mirror and two crossed reflecting surfaces via two light channels. Each light channel comprises a folding mirror and an eyepiece consisting of three lenses. The exit pupils of the head-mounted display are assumed to coincide with the user's pupils. The image is imaged on the retina of both eyes of the user.
A drawback of the head-mounted display described in this application is that the large number of lenses and mirrors render the design relatively expensive and heavy. Instead of glass, inexpensive materials such as, for example synthetic resin material may be used. However, this has the drawback that the image realized thereby has a considerably poorer quality.
It is known per se to reduce the number of optical components by replacing the three-lens eyepieces by single-lens eyepieces, with one of its surfaces having a diffractive structure. This has the drawback that its picture quality is decreased because the eyepiece comprises one lens only. Moreover, two diffractive structures are to be provided on a curved surface.